Pivotable drum arm support



Sept. 15, 1964 s. N. IRWIN ETAL 3,148,615

PIVOTABLE DRUM ARM SUPPORT Filed Oct. 5, 1961 4 Sheets-Sheet l Sept 15, 1964 s. N. IRWIN ETAL 3,148,615

I' PIvoTABLE DRUM ARM SUPPORT Filed Oct. 3, 1961 4 Sheets-Sheet 2 Sept. l5, 1964 s. N. IRWIN ETAL. 3,148,615

PIVOTABLE DRUM ARM SUPPORT Filed oct. a, 1961 4 Sheets-Sheet 5 Sept 15, 1954 s. N. IRWIN ETAL 3,148,615

^ PIVOTABLE DRUM ARM SUPPORT Filed Oct. 3, 1961 4 Sheets-Sheet 4 United States Patent O 3,148,615 PIV @TABLE DRUM ARM SUPPORT Samuel N. Irwin, Grosse Pointe Woods, Arvin D. Mc- Gregor, Birmingham, and Earl G. Goetsch and Theodore A. Jackson, Detroit, Mich., assignors, by mesne assignments, to Holley Computer Products Company,

Warren, Mich., a corporation of Michigan Filed Get. 3, 1961, Ser. No. 142,642

3 Claims. (Cl. 101-102) This invention relates to printers, and more particularly to a pivotable drum and ribbon drive support member such as that employed in the printer disclosed in U.S. application Serial No. 138,157, tiled on September 14, 1961, in the names of Arvin D. McGregor and James M. Irvine, Jr.

Most printers, including the above disclosed printer, have a set of print hammers disposed along a printing station, a supported print drum or other means of presenting characters to be printed along the printing station and means for driving a sheet of paper or other record strip between the print hammers and the member carrying the characters so that the hammers may impact or otherwise drive the paper into the characters. During printing, the print drum is necessarily very close to the print hammers. However, in order that the printer operator may load and unload the paper, it is necessary that either the print drum or other member bearing the characters or the bank of print hammers be somehow movable.

Accordingly, an object of the invention is to provide a printer in which the print drum and ribbon drive support member is mounted so as to be pivotable from a horizontal operative or print position to a vertical inoperative or non-print position. In other words, the support arm is pivotable through a vertical plane so that the printer does not occupy any additional floor space when paper is being loaded.

Another more specific object of the invention is to provide a print drum and ribbon drive support member that is pivotable to a vertical position about a horizontal pivot pin, the pin having means associated therewith urging the arm to the vertical position so as to assist the operator in lifting the arm when it is desired to load paper.

These and other objects and advantages of the invention will become more apparent upon reference to the following specication and drawings wherein:

FIGURE l is a perspective view of a printer embodying the invention;

FIGURE 2 is a perspective view taken from the other end of the printer;

FIGURE 3 is a perspective view taken from the same end of the printer as FIGURE l, but with the print drum support arm in a non-print position;

FIGURE 4 is an enlarged fragmentary portion of FIG- URE 2 illustrating the print drum support member in the unlocked position;

FIGURE 5 is an enlarged cross-sectional view taken on the plane of line 5 5 of FIGURE l illustrating the pivot means for the print drum support member;

FIGURE 6 is a schematic perspective view illustrating the manner in which the print drum is driven.

The above. described drawings are duplicates of certain of the drawings in the above referenced application Serial No. 138,157, the disclosure of which is incorporated herein to any extent that it may be necessary to complete this disclosure.

Referring now to the drawings in greater detail, it will be seen that the print drum and ribbon drive elements are mounted on a suitably formed, relatively elongated casting or other support member 273 that is pivotally 3,148,615 Patented Sept. 15, 1964 secured to the printer main frame 101 of the printer 100 on the horizontally disposed pivot pin 274 so that the casting 273 may be raised from the horizontal print position of FIGURE 1 to the vertical non-print position of FIGURE 3. It will be noted from FIGURE 5 that the pivot pin 274 is secured to the casting 273 by the pin 376 ICC ' and that it has secured thereto the inner end of a coil spring 275, the outer end 276 of the coil spring being secured to the main support casting 101. The coil spring 275 is secured in a manner so that it assumes a wound-up condition when the drum arm casting 273 is lowered to its printing position; thus, the coil spring 275 supplies a force to assist the printer operator in raising the drum arm casting when it is desired to load or unload paper.

The pivoted end of the drum arm casting 273 is formed hollow to receive a longitudinally fixed shaft 301 mounted in a set of suitable bearings 302. The extreme outer end of shaft 301 is formed with a reduced portion so as to provide a shoulder 306. An annular abutment member 307 having an outer face 308 aligned with the shoulder 306 is secured to the shaft 301 by any suitable means such as a set screw, the abutment member having a locating pin 309 extending beyond its outer face. The shaft 301 is also tted with the code disk 310 of a socalled code disk assembly 272, the code disk comprising a disk of transparent material on which concentric rings of alternating opaque areas constituting a code are formed, the code disk having a central annular opening at which the annular mounting members 311 and 312 are secured by any means such as screws. The mounting members 311 and 312 are also formed with aligned central openings to enable the code disk to be mounted on the reduced end portion of the shaft 301, the mounting member 311 being placed in abutment member 307 so that the locating pin 309 is received in a locating slot 313 formed in the mounting member 311.

The print drum 109 is preferably a hollow cylinder made of any suitable material and having the rows of characters 161 suitably formed on the outer surface thereof. The inner ends of the drum are formed with conical surfaces 314 that match the conical surfaces 299 and 304 on the disks 298 and 303, respectively. The drum is placed in the printer by retracting the disk 298, applying the end of the drum having the groove or notch 315 formed therein over the disk 303 so that the locating lug 305 is received in the notch 315, lowering the other end of the drum and then forcing the lever 285 to the left in FIGURE 2 so that the disk 298 enters an engages the drum under the force of the compressed spring 289. Removal of the drum is accomplished by the opposite procedure. From the above, it is apparent that drums having only alpha, only numeric, alpha and numeric and different style characters may be quickly interchanged in the printer, provided, of course, that a suitable matching code disk 310 is employed with any particular drum.

The positioning lug 305 is, of course, employed so as to accurately position the drum 109 with respect to the shaft 301. Likewise, the locating pin 309 accurately positions the code disk 310 with respect to the shaft 301. The positions of the lug 305 and the locating pin 309 are such that the code disk 310 having the rings 316 of alternating opaque areas, when used in conjunction with a photodiode assembly, is able to identify a particular row of characters 161 on the print drum that is approaching the row of printing hammers 160.

The purpose of the code disk assembly 272 is to produce a signal identifying which row of characters formed on the drum 109 can next be printed; that is, this signal identities the location of the characters on the drum while the printer is in operation. Since it is desirable to use the code disk is made interchangeable by the use of a simple, spring-loaded, bayonet type quick-release mechanism 317 comprising a pin 318 extending from opposite sides of shaft portion 319 and adapted to be engaged in the annular groove 320 formed in a locking member 321. The locking member 321 is retained in the locked position by means of a compression spring 322 positioned between the locking member and annular plate member 323 movably fixed within the locking member and having a face engaging the outer abutment member 312. The locking member 321 is removed by slight pressure toward the code disk 310 and turning the same in either direction so that the ends of the pin 318 can pass through suitable openings formed in the flange 324 of the locking member, at which time the spring 322 snaps the locking member 321 outwardly so that it can be removed from the shaft portion 319. The code disk 310 can then be pulled off the shaft. The code disk 310 can be replaced or a new code disk can be assembled and locked on the shaft portion 319 by the reverse operation of the locking member 321.

A photodiode assembly (not shown) is also secured to the drum arm casting 273 in a manner so that a row of photodiodes is positioned radially with respect to the code disk 310 adjacent the inner side thereof.

A lamp 340 is mounted on the end of the drum arm casting 273, and a cylindrical lens 341 made of any suitable plastic or other light refracting material is mounted between the lamp 340 and the code disk 310 to refract a line of light impinging on any photodiode that is not blocked by an opaque area on the code disk. Since the print drum and the code disk are properly aligned and locked in place, it is apparent that photodiodes will signal character position, it being understood that each different print drum requires its own properly formed code disk.

From the above description and from the description of the main drive group, it is apparent that the drum 109 and the code disk 310 are driven together whenever the drum arm group is locked in the FIGURE 1 position and power is supplied to the printer. It is important that the drum drive should be rendered inoperative whenever the drum 109 is not in its horizontal position and locked, the operative or print position of the drum being when the pin 342 extending from the outer end of the drum casting is resting in the wedge block 343 secured to the printer main frame 101 and locked in place by any suitable clamp assembly 344, as shown in FIGURE 2. The clamp 344 may be of any suitable design, such as toggle clamp Model No. 208 sold by the Detroit Stamping Company, and it is apparent from FIGURE 2 that movement of the clamp handle 345 to the vertical position causes the locking bar portion 346 to pivot in the manner to engage the top of the pin 342, thereby retaining it in the wedge of the block 343.

As stated above, it is necessary to prevent operation of the drum 109 unless the drum is in its horizontal print position and locked in place. This is accomplished by an interlock system consisting of a switch 347, the contacts of which are closed by the lower surface 348 of the portion of the drum arm casting in which the pin 342 is secured, and another double switch 349, the contacts of which are closed by the lower portion 350 of the handle of the clamp when it is in the vertical position. This interlock system is shown best in FIGURES 2 and 4. Unless both switches 347 and 349 are closed, power cannot be supplied to the main drive motor 107.

The drum arm support also includes a complete print ribbon drive mechanism 271, the details of which include a ribbon drive motor 351, an intermediate shaft 352, a pulley 354, a belt 355, clutch coupling devices 356, coil springs 361, a shaft 358, ribbon spools 359, and a ribbon 162, all of which are described fully in application Serial No. 138,157 and thus need not be described here.

As explained in the above referenced application Serial No. 138,157 and as shown in FIGURE 6, the printer 4 drive train is comprised essentially of a belt and pulley system. In connection with the invention, it will be noted that the print drum is driven by the pulleys 152 and 153 and the belt 155. All of the belts and pulleys are of the non-slipping type so as to maintain a predetermined drive relation between the parts of the printer. The belt drive for the print drum also provides a relatively inexpensive means of enabling the print drum casting 273 to be pivoted out of its print position without in any way interfering with the predetermined relation of the drum drive and the other parts of the printer. This is seen in FIGURE 3 where it will be observed that the belt merely twists on the spring-loaded tensioning pulley 156 when the support is raised.

The printer drive train further includes a paper moving mechanism which includes two separate subassemblies, a paper tractor drive mechanism 139 that actually drives the paper and a so-called format control assembly 375 that signals the amount that the paper should be advanced. As best seen in FIGURE 6, the two subassemblies 139 and 375 are both driven from the main drive motor 107 through a paper advance spring clutch mechanism 128, the operation of which directly affects the paper movement.

The tractor drive assembly 139 includes a drive shaft 382, which is suitably mounted in bearings in the two end supports 102 and 103 and a second stationary guide shaft 383 also mounted in these two end supports. The paper on which printing is to be done can be of any standard width, and it is formed as usual with perforations along the edges thereof so that it can be driven by the teeth 380 around the drive wheels 384 and the idler wheels 385 of the paper drive tractors 381. Any suitable clamp type adjusting device 386 (FIGURE 2) may be used to enable the individual tractors 381 to be adjusted horizontally along the shafts 382 and 383. Additional details of the paper moving mechanism 110 are fully described in application Serial No. 138,157.

It is apparent from the above description that a printer embodying the invention includes a separate member on which the print drum or other character presenting mechanism and/or the ribbon drive mechanism are supported. This separate member may be moved from a print position, at which time the print drum is disposed adjacent the print hammers, to a non-print position, at which time the support member is completely removed from the paper drive mechanism so that the entire paper or other record strip is exposed. This obviously provides complete and easy access to the paper drive mechanism, and it eliminates some of the relatively awkward methods of loading paper in known prior art printers.

Movement of this support member on a single pivot or about one end thereof also completely exposes the print drum, the ribbon drive mechanism and other parts of the printer so that any work necessary on these mechanisms is much more easily accomplished. This would be true regardless of direction in which the support member is moved. Additionally, however, the specific embodiment of the invention disclosed herein provides for the movement of the support member to a vertical position; this gives the added advantages of safety and keeping the floor space required for the printer to a minimum. In other words, moving the support member to enable loading of the paper does not result in the support arm projecting horizontally into the space around the printer where it could be damaged or where someone could accidentally bump into it.

While but one embodiment of the invention has been disclosed, it is apparent that other modifications are possible, and no limitations are intended, except as recited in the following claims.

What we claim as our invention is:

1. A printer, comprising a main frame, a main drive motor, a printing station, means operated by said motor for driving a record strip through said printing station, a

print drum having characters formed thereon, said print drum being mounted for rotation by said motor on a support member, said support member being secured at one end thereof to said main frame on a pivot so as to be pivotable from a print position to a non-print position, means associated with said pivot for continuously urging said support member to said non-print position, means for locking said support member in the print position against the force of said urging means and means for preventing power from being supplied to said main drive motor until said support member is locked in said print position.

2. A printer, comprising a main support, a main drive motor, a second support member pivotally secured at one end thereof to said main support, a print drum having characters to be printed formed thereon and mounted for rotation by said motor on said second support member, means operated by said motor for driving a record strip past said print drum, means for driving a print ribbon adjacent said print drum, said print ribbon driving means being mounted on said second support member, said second support member being movable from a horizontal position to a vertical position so as to completely expose and permit access to said record strip driving means, and means for preventing power from being supplied to said main drive motor and to said print ribbon driving means until said second support member is disposed in said horizontal position.

3. In a printer including a main frame, a main drive motor, a separate support having mounted therein a member on which characters to be printed are formed, said separate support also having mounted thereon means for driving a print ribbon past said member and means operated by said motor form rotating said member, means operated by said motor for driving a record strip past said member, said separate support being secured to said main frame on a pivot so that saidsupport and al1 of said elements mounted thereon may be rotated from a printing position across said record strip to a vertical nonprint position at which time said record strip is completely unobstructed by said support, means continuously urging said support towards said non-print position, means for locking said support in said print position, said locking means including a clamp for retaining said support against said main frame, and means for preventing power from being supplied to said main drive motor and to said print ribbon driving means until said support member is locked in said print position.

References Cited in the le of this patent UNITED STATES PATENTS 459,093 Blickensderfer Sept. 8, 1891 1,523,480 Grandjean Jan. 20, 1925 2,230,682 Fuller Feb. 4, 1941 2,264,855 Pasinski Dec. 2, 1941 2,542,868 Hart et al. Feb. 20, 1951 2,599,278 Osgood June 2, 1952 2,729,323 Jones Jan. 3, 1956 2,780,165 Kuhn Feb. 5, 1957 2,799,222 Goldberg et al July 16, 1957 2,825,559 Davidson Mar. 4, 1958 

3. IN A PRINTER INCLUDING A MAIN FRAME, A MAIN DRIVE MOTOR, A SEPARATE SUPPORT HAVING MOUNTED THEREIN A MEMBER ON WHICH CHARACTERS TO BE PRINTED ARE FORMED, SAID SEPARATE SUPPORT ALSO HAVING MOUNTED THEREON MEANS FOR DRIVING A PRINT RIBBON PAST SAID MEMBER AND MEANS OPERATED BY SAID MOTOR FORM ROTATING SAID MEMBER, MEANS OPERATED BY SAID MOTOR FOR DRIVING A RECORD STRIP PAST SAID MEMBER, SAID SEPARATE SUPPORT BEING SECURED TO SAID MAIN FRAME ON A PIVOT SO THAT SAID SUPPORT AND ALL OF SAID ELEMENTS MOUNTED THEREON MAY BE ROTATED FROM A PRINTING POSITION ACROSS SAID RECORD STRIP TO A VERTICAL NON-PRINT POSITION AT WHICH TIME SAID RECORD STRIP IS COMPLETELY UNOBSTRUCTED BY SAID SUPPORT, MEANS CONTINUOUSLY URGING SAID SUPPORT TOWARDS SAID NON-PRINT POSITION, MEANS FOR LOCKING SAID SUPPORT IN SAID PRINT POSITION, SAID LOCKING MEANS INCLUDING A CLAMP FOR RETAINING SAID SUPPORT AGAINST SAID MAIN FRAME, AND MEANS FOR PREVENTING POWER FROM BEING SUPPLIED TO SAID MAIN DRIVE MOTOR AND TO SAID PRINT RIBBON DRIVING MEANS UNTIL SAID SUPPORT MEMBER IS LOCKED IN SAID PRINT POSITION. 